The F-GT is a solid upgrade from a desk setup and will feel like a completely different experience with your T300. It locks the wheel, pedals and seat together, gives you far better stability, and lets you finally brake properly without the chair moving. The formula and GT seating options are a nice bonus, and for your current wheel it is more than strong enough.

The main limitations are the seat being only average and the cockpit being a bit tight for bigger drivers. It can also flex slightly if you upgrade to very strong load cell or hydraulic pedals later, but for a T300 and a normal load cell it is fine.

If you think you will upgrade to a powerful direct drive wheel in the future, then an aluminium profile rig like a GT Omega Prime Lite, Sim-Lab GT1 Evo or Trak Racer TR80 is a better long term platform. If your plan is simply to get off the desk and have a stable, comfortable cockpit that works with mid range gear, the F-GT is a perfectly good choice.